The course website and blog for the Fall 2015 instance of Penn State's SC200 course

Tag Archives: anatomy

Nostalgia is one of my greatest weaknesses, I think. For such a long time I’ve been severely missing aspects of my childhood, and often these memories are a source of depression. For me, nostalgia prevents me from moving forward. However, I know many other people experience nostalgia as a calming mechanism and can easily look back on happy memories without any emotional turmoil in the present. “‘When you’re nostalgic about something, there’s a little bit of a sense of loss—[the moment has] happened, it’s gone—but usually the net result is happiness,’ says Clay Routledge, a social psychologist at North Dakota State University, who, with several other researchers, has studied the emotion extensively over the past decade.” Either way, experiencing nostalgia definitely influences mood, and can affect how we live our lives. So where does it come from?

Routledge conducted a study on the possible triggers of nostalgia (found here). Participants were asked to describe situations that lead to experiencing nostalgia, and scientists found that negative emotions, chiefly loneliness, were the most common answers. This makes sense, going along with Routledge’s initial statement- nostalgia is possibly brought about in an attempt to cope with any negative mental state someone may find himself or herself in. Routledge refers to these as “psychological threats.” But if this is the case, it doesn’t make sense that my negative mental states often come from the nostalgia itself. Also, this study is observational, and results may be confounded by third variables such as the age of the participant or possible mental disorders. I would need an actual experiment studying the levels of brain chemicals during episodes of nostalgia to be completely convinced that nostalgia is brought about by a negative mental state.

Upon doing some more digging, I thought it was a bit odd that many news articles studying nostalgia and its effects cite the same study by Routledge (and on some occasions, nothing else.) I find it hard to believe that there are so few modern studies conducted on this topic of psychology. There are several older studies that take a more negative view on the effects of nostalgia, but the only study used to inform the public about the new light scientists are seeing the nostalgia issue under is the one conducted at North Dakota State University. The findings of the study do look decent, and many researchers were involved, but there should be more scientists doing similar experiments in order to reduce the likelihood of chance.

I am a violist in Penn State’s Philharmonic Orchestra, and after a long two hour rehearsal, my fingers are often stiff and I’m just itching to crack my knuckles to relieve myself of the tension. There are some people who are chronic knuckle crackers, and then there are people like my mom (who freaks out and tells me I’ll get arthritis if I keep doing that). What I want to know is if there is actual scientific evidence that suggests cracking your knuckles is bad for your joints, or if it’s just a myth made up by people who get grossed out by the popping noise.

John Indalecio, a hand therapist at the Hospital for Special Surgery in New York, believes there is not enough compelling scientific evidence to suggest that knuckle-cracking will cause arthritis. However, if a habit is formed, there is a chance that more problems could occur down the road. Sounds reasonable to me, but the first article I found was from Huffington Post, so I think I’ll need to look at the actual studies to see if the results support this claim.

A PLOS ONE study concludes, “Presently, the literature in this area is confusing in that the energy produced during joint cracking is though to exceed the threshold for damage[51], but habitual knuckle cracking has not been shown to increase joint degeneration [52]. Ultimately, by defining the process underlying joint cracking, its therapeutic benefits, or possible harms, may be better understood.” In a nutshell: making cracking your knuckles a habit has NOT been shown to cause an increase in joint issues. More experiments would need to be done in order to further assess the long-term effects.

What I’m wondering is if there has ever been a study examining the effect of knuckle-cracking on many different people considering the genetics one may have to make them more prone to joint or muscle issues. If you have a family history of arthritis or osteoporosis, for example, does the effect of cracking your knuckles worsen? Are there benefits to having certain types of people crack their knuckles to create these cavities in the finger joints?

Another thing- the PLOS ONE study was definitely very thorough, but the average person would find it difficult to get the big picture of what the scientists discovered. For so long, everyone believed (and some still believe) the sound of cracking knuckles came from air bubbles being popped, but this study proves otherwise. I think the information would be much more accessible to the general public and less likely to be misunderstood if another version of the study was published simplifying the findings and explaining what they mean for us.